Crane bridge



May 29, 1928.

J. A. SHEPARD CRANE BRIDGE Filed Sept. 16, 1927 INVENTOR g: TTORNEY Patented May 29, 1928.

UNITED STATES. PATENT OFFICE."

JAMES A. SHEPARD, OF MONTOUR FALLS, NEW YORK, ASSIGNOR T0 SHEPARD ELEG- IRIG CRANE & HOIST COMPANY, OF MONTOUR FALLS, NEW YORK, A CORPORATION OF NEW YORK.

CRANE BRIDGE.

Application filed SeptemberIG, 1927. Serial No. 219,958.

The general object of the present inven-f tion is to provide an improved crane bridge characterized by its mechanical simplicity and by the manner in which the strength and rigidity required to withstand the stresses to which the structure is subjected, "1s secured with a bridge structure lighter in weight and simpler in form than has hereto- I fore been required under similar conditions of use. ldore specifically, the object'of the invention is to provide a travelling crane bridge having its main beam or girder elements so reinforced and supported to withstand stresses tending to bend and twist said elements that the latter may each'be formed :-reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

Of the drawings:

Fig. 1 is a somewhat diagrammatic plan 'view of an overhead travelling crane struc-' ture;

Fig. 2 is a perspective view of a portion of the bridge structure and Fig. 3 is a partial section on the line 33 of Fig. 1.

The travelling crane structure shown somewhat diagrammatically in Fig. 1, comprises a bridge composed of two main girder elements A connected at their opposite ends to crane and frame members B in which are journalled the bridge supporting wheels C which run on rails D carried by stationary supports 1). The crane is propelled along the rails D by a motor E located at one side of the space bet-ween the girder A and secured to the side of one of the latter. The tops of the girders A serve as, or as shown, support track rails a for the supporting wheels of a trolley F on which is mounted the motor driven hoist and the motor for propelling the trolley along the rails a. G represents a depending operators cage which stresses.

ordinarily, and as shown, depends from the bridge structure at one side of the space between the girdersA and is supported wholly by one of the latter or partly by one of the latter and by one of the end frames of the bridge. Ordinarily, and as shown, there is a walkway g running alongside the girder A at the side of the bridge at which the cage G is located.

In so far as already described, the con struction shown in Fig. 1 rep'resents the usual and regular practice of the prior art;

In such a crane structure the girders A must not only be strong. enough and stilf enougl' to safely support the maximum static load imposed by their own weight and the weights of the parts carried by them-includmg whatever weight may be suspended from the hoist f on the trolley F, but must have strength and stiffness to prevent significant bending or twisting of the girders. The bending girders are subjected are relatively large, and arisefrom various causes. Of these causes the one ordinarily most important is the reaction on the bridge of the means for propelling the bridge along the rails D the torque of the armature of the motor E subjecting the frame of that motor to an opposing torque. The weight of the bridge propelling means, the walkway g'and the cage F all of which are ordinarily located at one side of the space between-the beams A to provide clearance for the hoist chain or chains, subjects the girder A by which they are supported, to. substantial torsional Furthermore, the starting and stopping of the crane in its movements along the trackrails D subject the girder to inertia and momentum effects tending to deflect the latter horizontally.

In accordance with the prefent invention,

from the girder A to'which it is attached,

and the attachment to the girder is made in such manner that the support acts on the and torsional stresses to which the shown each such channel bar part is connected tothe corresponding girder A by a suitable metal plate H having a portion flat against the vertical web of the girder A and secured to the latter by rivets H suit ably distributed vertically and longitudinalby rivets H ly of the girder web. Each plate H comprises another portion bent away from the f girder into parallelism with the corresponding channel bar portion of the support and secured to the vertical web of the latter as Ordinarily, and as shown, the vertical web of the channel bar portion of each support islless than the vertical depth of the web of the girder A, and each plate H may well be sheared off to give it the tapered form shown in the drawings.

The cage Gr may be supported in part by one or more hanger bolts G from the adjacent support H. I

With the described arrangement, the supports I-I offer effective resistance to the tendency of the girders A to be twisted or horizontally deflected by the torsional and deflecting stresses to which they are subjected by the operation of the bridge drive, by the eccentrically disposed load carried by the girders, and by the inertia and momentum effects resulting from the relatively rapid starting and stopping of the crane movements along supports D. Furthermore, the supports H give the girders A additional static load carrying strength by increasing the resistance against any tendencyof the top or compression flange of each girder A to buckle sideways underits load.

The crane bridge construction illustrated and described is obviously simple and effective, and the reinforcement of the main girders A in the manner described, has been found inpractice to permit those girders to be formed of simple rolledbars under conditions, as to girder length and load supported, which have heretofore made it essential to employ composite or box girders. The use of the invention thus materially detin es be employed'without a corresponding.

use of other features.

Having now described my invention, what I claim as new and desire to secure by Let'- ters Patent, is:

1. The combination in a travelling crane bridge comprising an end frame and a girder connected at one end to said end frame and having a vertical girder reinforcement attachedto the web ofthe girder at vertical points located at adistan'ce from said end frame, said reinforcement extending diagonally away from the girder into engagement with the end frame and being attached to the latter.

2. The combination in a travelling crane bridge comprising an end frame and a girder connected at one end to said end frameand formed with a vertical web, of a girderreiIlfOlCGlIleIlt comprising a plate having a portion connected to a portion of said'web intermediate the ends of the girder at points distributed longitudinally and vertically 0f the girder intermediate the ends of the latter, and said plate having a second portion extending diagonally away from the girder, and means connecting said plate and end frame.

3. A travelling crane bridge comprising end frames, a pair of spaced apart parallel girders connecting said end frames and each formed of a rolled metal part having a vertical web and flanges at the upper and lower edges of the latter, and supports attachedto said webs or flanges intermediate the ends of thegirders and extending diagonally away from thegirdei's into engagement with the endframes, whereby said girders are strengthened against stresses tending .to twist or horizontally deflect them.

Signed at Montour Falls, in the county .of Schuyler, and State of New York, this 12th day of September A. D. 1927.

JAMES A. SHEPARD; 

